# ai_instance.cpp

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    00001 /* $Id: ai_instance.cpp 15614 2009-03-04 22:37:25Z yexo $ */
    00002
    00005 #include "../stdafx.h"
    00006 #include "../debug.h"
    00007 #include "../settings_type.h"
    00008 #include "../vehicle_base.h"
    00009 #include "../saveload/saveload.h"
    00010 #include "table/strings.h"
    00011
    00012 #include <squirrel.h>
    00013 #include "../script/squirrel.hpp"
    00014 #include "../script/squirrel_helper.hpp"
    00015 #include "../script/squirrel_class.hpp"
    00016 #include "../script/squirrel_std.hpp"
    00017
    00018 #define DEFINE_SCRIPT_FILES
    00019
    00020 #include "ai_info.hpp"
    00021 #include "ai_storage.hpp"
    00022 #include "ai_instance.hpp"
    00023
    00024 /* Convert all AI related classes to Squirrel data.
    00025  * Note: this line a marker in squirrel_export.sh. Do not change! */
    00026 #include "api/ai_abstractlist.hpp.sq"
    00027 #include "api/ai_accounting.hpp.sq"
    00028 #include "api/ai_airport.hpp.sq"
    00029 #include "api/ai_base.hpp.sq"
    00030 #include "api/ai_bridge.hpp.sq"
    00031 #include "api/ai_bridgelist.hpp.sq"
    00032 #include "api/ai_cargo.hpp.sq"
    00033 #include "api/ai_cargolist.hpp.sq"
    00034 #include "api/ai_company.hpp.sq"
    00035 #include "api/ai_controller.hpp.sq"
    00036 #include "api/ai_date.hpp.sq"
    00037 #include "api/ai_depotlist.hpp.sq"
    00038 #include "api/ai_engine.hpp.sq"
    00039 #include "api/ai_enginelist.hpp.sq"
    00040 #include "api/ai_error.hpp.sq"
    00041 #include "api/ai_event.hpp.sq"
    00042 #include "api/ai_event_types.hpp.sq"
    00043 #include "api/ai_execmode.hpp.sq"
    00044 #include "api/ai_gamesettings.hpp.sq"
    00045 #include "api/ai_group.hpp.sq"
    00046 #include "api/ai_grouplist.hpp.sq"
    00047 #include "api/ai_industry.hpp.sq"
    00048 #include "api/ai_industrylist.hpp.sq"
    00049 #include "api/ai_industrytype.hpp.sq"
    00050 #include "api/ai_industrytypelist.hpp.sq"
    00051 #include "api/ai_list.hpp.sq"
    00052 #include "api/ai_log.hpp.sq"
    00053 #include "api/ai_map.hpp.sq"
    00054 #include "api/ai_marine.hpp.sq"
    00055 #include "api/ai_order.hpp.sq"
    00056 #include "api/ai_rail.hpp.sq"
    00057 #include "api/ai_railtypelist.hpp.sq"
    00058 #include "api/ai_road.hpp.sq"
    00059 #include "api/ai_sign.hpp.sq"
    00060 #include "api/ai_station.hpp.sq"
    00061 #include "api/ai_stationlist.hpp.sq"
    00062 #include "api/ai_subsidy.hpp.sq"
    00063 #include "api/ai_subsidylist.hpp.sq"
    00064 #include "api/ai_testmode.hpp.sq"
    00065 #include "api/ai_tile.hpp.sq"
    00066 #include "api/ai_tilelist.hpp.sq"
    00067 #include "api/ai_town.hpp.sq"
    00068 #include "api/ai_townlist.hpp.sq"
    00069 #include "api/ai_tunnel.hpp.sq"
    00070 #include "api/ai_vehicle.hpp.sq"
    00071 #include "api/ai_vehiclelist.hpp.sq"
    00072 #include "api/ai_waypoint.hpp.sq"
    00073 #include "api/ai_waypointlist.hpp.sq"
    00074
    00075 #undef DEFINE_SCRIPT_FILES
    00076
    00077 /* static */ AIInstance *AIInstance::current_instance = NULL;
    00078
    00079 AIStorage::~AIStorage()
    00080 {
    00081   /* Free our pointers */
    00082   if (event_data != NULL) AIEventController::FreeEventPointer();
    00083   if (log_data != NULL) AILog::FreeLogPointer();
    00084 }
    00085
    00086 static void PrintFunc(bool error_msg, const SQChar *message)
    00087 {
    00088   /* Convert to OpenTTD internal capable string */
    00089   AIController::Print(error_msg, FS2OTTD(message));
    00090 }
    00091
    00092 AIInstance::AIInstance(AIInfo *info) :
    00093   controller(NULL),
    00094   storage(NULL),
    00095   engine(NULL),
    00096   instance(NULL),
    00097   is_started(false),
    00098   is_dead(false),
    00099   suspend(0),
    00100   callback(NULL)
    00101 {
    00102   /* Set the instance already, so we can use AIObject::Set commands */
    00103   GetCompany(_current_company)->ai_instance = this;
    00104   AIInstance::current_instance = this;
    00105
    00106   this->controller = new AIController();
    00107   this->storage    = new AIStorage();
    00108   this->engine     = new Squirrel();
    00109   this->engine->SetPrintFunction(&PrintFunc);
    00110
    00111   /* The import method is available at a very early stage */
    00112   this->engine->AddMethod("import", &AILibrary::Import, 4, ".ssi");
    00113
    00114   /* Register the AIController */
    00115   SQAIController_Register(this->engine);
    00116
    00117   /* Load and execute the script for this AI */
    00118   const char *main_script = info->GetMainScript();
    00119   if (strcmp(main_script, "%_dummy") == 0) {
    00120     extern void AI_CreateAIDummy(HSQUIRRELVM vm);
    00121     AI_CreateAIDummy(this->engine->GetVM());
    00122   } else if (!this->engine->LoadScript(main_script)) {
    00123     this->Died();
    00124     return;
    00125   }
    00126
    00127   /* Create the main-class */
    00128   this->instance = MallocT<SQObject>(1);
    00129   if (!this->engine->CreateClassInstance(info->GetInstanceName(), this->controller, this->instance)) {
    00130     this->Died();
    00131     return;
    00132   }
    00133
    00134   /* Register the API functions and classes */
    00135   this->RegisterAPI();
    00136
    00137   /* The topmost stack item is true if there is data from a savegame
    00138    * and false otherwise. */
    00139   sq_pushbool(this->engine->vm, false);
    00140 }
    00141
    00142 AIInstance::~AIInstance()
    00143 {
    00144   if (instance != NULL) this->engine->ReleaseObject(this->instance);
    00145   if (engine != NULL) delete this->engine;
    00146   delete this->storage;
    00147   delete this->controller;
    00148   free(this->instance);
    00149 }
    00150
    00151 void AIInstance::RegisterAPI()
    00152 {
    00153 /* Register all classes */
    00154   squirrel_register_std(this->engine);
    00155   SQAIAbstractList_Register(this->engine);
    00156   SQAIAccounting_Register(this->engine);
    00157   SQAIAirport_Register(this->engine);
    00158   SQAIBase_Register(this->engine);
    00159   SQAIBridge_Register(this->engine);
    00160   SQAIBridgeList_Register(this->engine);
    00161   SQAIBridgeList_Length_Register(this->engine);
    00162   SQAICargo_Register(this->engine);
    00163   SQAICargoList_Register(this->engine);
    00164   SQAICargoList_IndustryAccepting_Register(this->engine);
    00165   SQAICargoList_IndustryProducing_Register(this->engine);
    00166   SQAICompany_Register(this->engine);
    00167   SQAIDate_Register(this->engine);
    00168   SQAIDepotList_Register(this->engine);
    00169   SQAIEngine_Register(this->engine);
    00170   SQAIEngineList_Register(this->engine);
    00171   SQAIError_Register(this->engine);
    00172   SQAIEvent_Register(this->engine);
    00173   SQAIEventCompanyBankrupt_Register(this->engine);
    00174   SQAIEventCompanyInTrouble_Register(this->engine);
    00175   SQAIEventCompanyMerger_Register(this->engine);
    00176   SQAIEventCompanyNew_Register(this->engine);
    00177   SQAIEventController_Register(this->engine);
    00178   SQAIEventDisasterZeppelinerCleared_Register(this->engine);
    00179   SQAIEventDisasterZeppelinerCrashed_Register(this->engine);
    00180   SQAIEventEngineAvailable_Register(this->engine);
    00181   SQAIEventEnginePreview_Register(this->engine);
    00182   SQAIEventIndustryClose_Register(this->engine);
    00183   SQAIEventIndustryOpen_Register(this->engine);
    00184   SQAIEventStationFirstVehicle_Register(this->engine);
    00185   SQAIEventSubsidyAwarded_Register(this->engine);
    00186   SQAIEventSubsidyExpired_Register(this->engine);
    00187   SQAIEventSubsidyOffer_Register(this->engine);
    00188   SQAIEventSubsidyOfferExpired_Register(this->engine);
    00189   SQAIEventVehicleCrashed_Register(this->engine);
    00190   SQAIEventVehicleLost_Register(this->engine);
    00191   SQAIEventVehicleUnprofitable_Register(this->engine);
    00192   SQAIEventVehicleWaitingInDepot_Register(this->engine);
    00193   SQAIExecMode_Register(this->engine);
    00194   SQAIGameSettings_Register(this->engine);
    00195   SQAIGroup_Register(this->engine);
    00196   SQAIGroupList_Register(this->engine);
    00197   SQAIIndustry_Register(this->engine);
    00198   SQAIIndustryList_Register(this->engine);
    00199   SQAIIndustryList_CargoAccepting_Register(this->engine);
    00200   SQAIIndustryList_CargoProducing_Register(this->engine);
    00201   SQAIIndustryType_Register(this->engine);
    00202   SQAIIndustryTypeList_Register(this->engine);
    00203   SQAIList_Register(this->engine);
    00204   SQAILog_Register(this->engine);
    00205   SQAIMap_Register(this->engine);
    00206   SQAIMarine_Register(this->engine);
    00207   SQAIOrder_Register(this->engine);
    00208   SQAIRail_Register(this->engine);
    00209   SQAIRailTypeList_Register(this->engine);
    00210   SQAIRoad_Register(this->engine);
    00211   SQAISign_Register(this->engine);
    00212   SQAIStation_Register(this->engine);
    00213   SQAIStationList_Register(this->engine);
    00214   SQAIStationList_Vehicle_Register(this->engine);
    00215   SQAISubsidy_Register(this->engine);
    00216   SQAISubsidyList_Register(this->engine);
    00217   SQAITestMode_Register(this->engine);
    00218   SQAITile_Register(this->engine);
    00219   SQAITileList_Register(this->engine);
    00220   SQAITileList_IndustryAccepting_Register(this->engine);
    00221   SQAITileList_IndustryProducing_Register(this->engine);
    00222   SQAITileList_StationType_Register(this->engine);
    00223   SQAITown_Register(this->engine);
    00224   SQAITownList_Register(this->engine);
    00225   SQAITunnel_Register(this->engine);
    00226   SQAIVehicle_Register(this->engine);
    00227   SQAIVehicleList_Register(this->engine);
    00228   SQAIVehicleList_DefaultGroup_Register(this->engine);
    00229   SQAIVehicleList_Group_Register(this->engine);
    00230   SQAIVehicleList_SharedOrders_Register(this->engine);
    00231   SQAIVehicleList_Station_Register(this->engine);
    00232   SQAIWaypoint_Register(this->engine);
    00233   SQAIWaypointList_Register(this->engine);
    00234   SQAIWaypointList_Vehicle_Register(this->engine);
    00235
    00236   this->engine->SetGlobalPointer(this->engine);
    00237 }
    00238
    00239 void AIInstance::Continue()
    00240 {
    00241   assert(this->suspend < 0);
    00242   this->suspend = -this->suspend - 1;
    00243 }
    00244
    00245 void AIInstance::Died()
    00246 {
    00247   DEBUG(ai, 0, "The AI died unexpectedly.");
    00248   this->is_dead = true;
    00249
    00250   if (this->instance != NULL) this->engine->ReleaseObject(this->instance);
    00251   delete this->engine;
    00252   this->instance = NULL;
    00253   this->engine = NULL;
    00254 }
    00255
    00256 void AIInstance::GameLoop()
    00257 {
    00258   if (this->is_dead) return;
    00259   if (this->engine->HasScriptCrashed()) {
    00260     /* The script crashed during saving, kill it here. */
    00261     this->Died();
    00262     return;
    00263   }
    00264   this->controller->ticks++;
    00265
    00266   if (this->suspend   < -1) this->suspend++; // Multiplayer suspend, increase up to -1.
    00267   if (this->suspend   < 0)  return;          // Multiplayer suspend, wait for Continue().
    00268   if (--this->suspend > 0)  return;          // Singleplayer suspend, decrease to 0.
    00269
    00270   /* If there is a callback to call, call that first */
    00271   if (this->callback != NULL) {
    00272     try {
    00273       this->callback(this);
    00274     } catch (AI_VMSuspend e) {
    00275       this->suspend  = e.GetSuspendTime();
    00276       this->callback = e.GetSuspendCallback();
    00277
    00278       return;
    00279     }
    00280   }
    00281
    00282   this->suspend  = 0;
    00283   this->callback = NULL;
    00284
    00285   if (!this->is_started) {
    00286     try {
    00287       AIObject::SetAllowDoCommand(false);
    00288       /* Run the constructor if it exists. Don't allow any DoCommands in it. */
    00289       if (this->engine->MethodExists(*this->instance, "constructor")) {
    00290         if (!this->engine->CallMethod(*this->instance, "constructor")) { this->Died(); return; }
    00291       }
    00292       if (!this->CallLoad()) { this->Died(); return; }
    00293       AIObject::SetAllowDoCommand(true);
    00294       /* Start the AI by calling Start() */
    00295       if (!this->engine->CallMethod(*this->instance, "Start",  _settings_game.ai.ai_max_opcode_till_suspend) || !this->engine->IsSuspended()) this->Died();
    00296     } catch (AI_VMSuspend e) {
    00297       this->suspend  = e.GetSuspendTime();
    00298       this->callback = e.GetSuspendCallback();
    00299     }
    00300
    00301     this->is_started = true;
    00302     return;
    00303   }
    00304
    00305   /* Continue the VM */
    00306   try {
    00307     if (!this->engine->Resume(_settings_game.ai.ai_max_opcode_till_suspend)) this->Died();
    00308   } catch (AI_VMSuspend e) {
    00309     this->suspend  = e.GetSuspendTime();
    00310     this->callback = e.GetSuspendCallback();
    00311   }
    00312 }
    00313
    00314 void AIInstance::CollectGarbage()
    00315 {
    00316   if (this->is_started && !this->is_dead) this->engine->CollectGarbage();
    00317 }
    00318
    00319 /* static */ void AIInstance::DoCommandReturn(AIInstance *instance)
    00320 {
    00321   instance->engine->InsertResult(AIObject::GetLastCommandRes());
    00322 }
    00323
    00324 /* static */ void AIInstance::DoCommandReturnVehicleID(AIInstance *instance)
    00325 {
    00326   instance->engine->InsertResult(AIObject::GetNewVehicleID());
    00327 }
    00328
    00329 /* static */ void AIInstance::DoCommandReturnSignID(AIInstance *instance)
    00330 {
    00331   instance->engine->InsertResult(AIObject::GetNewSignID());
    00332 }
    00333
    00334 /* static */ void AIInstance::DoCommandReturnGroupID(AIInstance *instance)
    00335 {
    00336   instance->engine->InsertResult(AIObject::GetNewGroupID());
    00337 }
    00338
    00339 /* static */ AIStorage *AIInstance::GetStorage()
    00340 {
    00341   assert(IsValidCompanyID(_current_company) && !IsHumanCompany(_current_company));
    00342   return GetCompany(_current_company)->ai_instance->storage;
    00343 }
    00344
    00345 /*
    00346  * All data is stored in the following format:
    00347  * First 1 byte indicating if there is a data blob at all.
    00348  * 1 byte indicating the type of data.
    00349  * The data itself, this differs per type:
    00350  *  - integer: a binary representation of the integer (int32).
    00351  *  - string:  First one byte with the string length, then a 0-terminated char
    00352  *             array. The string can't be longer then 255 bytes (including
    00353  *             terminating '\0').
    00354  *  - array:   All data-elements of the array are saved recursive in this
    00355  *             format, and ended with an element of the type
    00356  *             SQSL_ARRAY_TABLE_END.
    00357  *  - table:   All key/value pairs are saved in this format (first key 1, then
    00358  *             value 1, then key 2, etc.). All keys and values can have an
    00359  *             arbitrary type (as long as it is supported by the save function
    00360  *             of course). The table is ended with an element of the type
    00361  *             SQSL_ARRAY_TABLE_END.
    00362  *  - bool:    A single byte with value 1 representing true and 0 false.
    00363  *  - null:    No data.
    00364  */
    00365
    00367 enum SQSaveLoadType {
    00368   SQSL_INT             = 0x00,
    00369   SQSL_STRING          = 0x01,
    00370   SQSL_ARRAY           = 0x02,
    00371   SQSL_TABLE           = 0x03,
    00372   SQSL_BOOL            = 0x04,
    00373   SQSL_NULL            = 0x05,
    00374   SQSL_ARRAY_TABLE_END = 0xFF,
    00375 };
    00376
    00377 static byte _ai_sl_byte;
    00378
    00379 static const SaveLoad _ai_byte[] = {
    00380   SLEG_VAR(_ai_sl_byte, SLE_UINT8),
    00381   SLE_END()
    00382 };
    00383
    00384 enum {
    00385   AISAVE_MAX_DEPTH = 25,
    00386 };
    00387
    00388 /* static */ bool AIInstance::SaveObject(HSQUIRRELVM vm, SQInteger index, int max_depth, bool test)
    00389 {
    00390   if (max_depth == 0) {
    00391     AILog::Error("Savedata can only be nested to 5 deep. No data saved.");
    00392     return false;
    00393   }
    00394
    00395   switch (sq_gettype(vm, index)) {
    00396     case OT_INTEGER: {
    00397       if (!test) {
    00398         _ai_sl_byte = SQSL_INT;
    00399         SlObject(NULL, _ai_byte);
    00400       }
    00401       SQInteger res;
    00402       sq_getinteger(vm, index, &res);
    00403       if (!test) {
    00404         int value = (int)res;
    00405         SlArray(&value, 1, SLE_INT32);
    00406       }
    00407       return true;
    00408     }
    00409
    00410     case OT_STRING: {
    00411       if (!test) {
    00412         _ai_sl_byte = SQSL_STRING;
    00413         SlObject(NULL, _ai_byte);
    00414       }
    00415       const SQChar *res;
    00416       sq_getstring(vm, index, &res);
    00417       /* @bug if a string longer than 512 characters is given to FS2OTTD, the
    00418        *  internal buffer overflows. */
    00419       const char *buf = FS2OTTD(res);
    00420       size_t len = strlen(buf) + 1;
    00421       if (len >= 255) {
    00422         AILog::Error("Maximum string length is 254 chars. No data saved.");
    00423         return false;
    00424       }
    00425       if (!test) {
    00426         _ai_sl_byte = (byte)len;
    00427         SlObject(NULL, _ai_byte);
    00428         SlArray((void*)buf, len, SLE_CHAR);
    00429       }
    00430       return true;
    00431     }
    00432
    00433     case OT_ARRAY: {
    00434       if (!test) {
    00435         _ai_sl_byte = SQSL_ARRAY;
    00436         SlObject(NULL, _ai_byte);
    00437       }
    00438       sq_pushnull(vm);
    00439       while (SQ_SUCCEEDED(sq_next(vm, index - 1))) {
    00440         /* Store the value */
    00441         bool res = SaveObject(vm, -1, max_depth - 1, test);
    00442         sq_pop(vm, 2);
    00443         if (!res) {
    00444           sq_pop(vm, 1);
    00445           return false;
    00446         }
    00447       }
    00448       sq_pop(vm, 1);
    00449       if (!test) {
    00450         _ai_sl_byte = SQSL_ARRAY_TABLE_END;
    00451         SlObject(NULL, _ai_byte);
    00452       }
    00453       return true;
    00454     }
    00455
    00456     case OT_TABLE: {
    00457       if (!test) {
    00458         _ai_sl_byte = SQSL_TABLE;
    00459         SlObject(NULL, _ai_byte);
    00460       }
    00461       sq_pushnull(vm);
    00462       while (SQ_SUCCEEDED(sq_next(vm, index - 1))) {
    00463         /* Store the key + value */
    00464         bool res = SaveObject(vm, -2, max_depth - 1, test) && SaveObject(vm, -1, max_depth - 1, test);
    00465         sq_pop(vm, 2);
    00466         if (!res) {
    00467           sq_pop(vm, 1);
    00468           return false;
    00469         }
    00470       }
    00471       sq_pop(vm, 1);
    00472       if (!test) {
    00473         _ai_sl_byte = SQSL_ARRAY_TABLE_END;
    00474         SlObject(NULL, _ai_byte);
    00475       }
    00476       return true;
    00477     }
    00478
    00479     case OT_BOOL: {
    00480       if (!test) {
    00481         _ai_sl_byte = SQSL_BOOL;
    00482         SlObject(NULL, _ai_byte);
    00483       }
    00484       SQBool res;
    00485       sq_getbool(vm, index, &res);
    00486       if (!test) {
    00487         _ai_sl_byte = res ? 1 : 0;
    00488         SlObject(NULL, _ai_byte);
    00489       }
    00490       return true;
    00491     }
    00492
    00493     case OT_NULL: {
    00494       if (!test) {
    00495         _ai_sl_byte = SQSL_NULL;
    00496         SlObject(NULL, _ai_byte);
    00497       }
    00498       return true;
    00499     }
    00500
    00501     default:
    00502       AILog::Error("You tried to save unsupported type. No data saved.");
    00503       return false;
    00504   }
    00505 }
    00506
    00507 /* static */ void AIInstance::SaveEmpty()
    00508 {
    00509   _ai_sl_byte = 0;
    00510   SlObject(NULL, _ai_byte);
    00511 }
    00512
    00513 void AIInstance::Save()
    00514 {
    00515   /* Don't save data if the AI didn't start yet or if it crashed. */
    00516   if (this->engine == NULL || this->engine->HasScriptCrashed()) {
    00517     SaveEmpty();
    00518     return;
    00519   }
    00520
    00521   HSQUIRRELVM vm = this->engine->GetVM();
    00522   if (!this->is_started) {
    00523     SQBool res;
    00524     sq_getbool(vm, -1, &res);
    00525     if (!res) {
    00526       SaveEmpty();
    00527       return;
    00528     }
    00529     /* Push the loaded savegame data to the top of the stack. */
    00530     sq_push(vm, -2);
    00531     _ai_sl_byte = 1;
    00532     SlObject(NULL, _ai_byte);
    00533     /* Save the data that was just loaded. */
    00534     SaveObject(vm, -1, AISAVE_MAX_DEPTH, false);
    00535     sq_poptop(vm);
    00536   } else if (this->engine->MethodExists(*this->instance, "Save")) {
    00537     HSQOBJECT savedata;
    00538     /* We don't want to be interrupted during the save function. */
    00539     bool backup_allow = AIObject::GetAllowDoCommand();
    00540     AIObject::SetAllowDoCommand(false);
    00541     if (!this->engine->CallMethod(*this->instance, "Save", &savedata)) {
    00542       /* The script crashed in the Save function. We can't kill
    00543        * it here, but do so in the next AI tick. */
    00544       SaveEmpty();
    00545       return;
    00546     }
    00547     AIObject::SetAllowDoCommand(backup_allow);
    00548
    00549     if (!sq_istable(savedata)) {
    00550       AILog::Error("Save function should return a table.");
    00551       SaveEmpty();
    00552       return;
    00553     }
    00554     sq_pushobject(vm, savedata);
    00555     if (SaveObject(vm, -1, AISAVE_MAX_DEPTH, true)) {
    00556       _ai_sl_byte = 1;
    00557       SlObject(NULL, _ai_byte);
    00558       SaveObject(vm, -1, AISAVE_MAX_DEPTH, false);
    00559     } else {
    00560       _ai_sl_byte = 0;
    00561       SlObject(NULL, _ai_byte);
    00562     }
    00563     sq_pop(vm, 1);
    00564   } else {
    00565     AILog::Warning("Save function is not implemented");
    00566     _ai_sl_byte = 0;
    00567     SlObject(NULL, _ai_byte);
    00568   }
    00569
    00570 }
    00571
    00572 /* static */ bool AIInstance::LoadObjects(HSQUIRRELVM vm)
    00573 {
    00574   SlObject(NULL, _ai_byte);
    00575   switch (_ai_sl_byte) {
    00576     case SQSL_INT: {
    00577       int value;
    00578       SlArray(&value, 1, SLE_INT32);
    00579       if (vm != NULL) sq_pushinteger(vm, (SQInteger)value);
    00580       return true;
    00581     }
    00582
    00583     case SQSL_STRING: {
    00584       SlObject(NULL, _ai_byte);
    00585       static char buf[256];
    00586       SlArray(buf, _ai_sl_byte, SLE_CHAR);
    00587       if (vm != NULL) sq_pushstring(vm, OTTD2FS(buf), -1);
    00588       return true;
    00589     }
    00590
    00591     case SQSL_ARRAY: {
    00592       if (vm != NULL) sq_newarray(vm, 0);
    00593       while (LoadObjects(vm)) {
    00594         if (vm != NULL) sq_arrayappend(vm, -2);
    00595         /* The value is popped from the stack by squirrel. */
    00596       }
    00597       return true;
    00598     }
    00599
    00600     case SQSL_TABLE: {
    00601       if (vm != NULL) sq_newtable(vm);
    00602       while (LoadObjects(vm)) {
    00603         LoadObjects(vm);
    00604         if (vm != NULL) sq_rawset(vm, -3);
    00605         /* The key (-2) and value (-1) are popped from the stack by squirrel. */
    00606       }
    00607       return true;
    00608     }
    00609
    00610     case SQSL_BOOL: {
    00611       SlObject(NULL, _ai_byte);
    00612       if (vm != NULL) sq_pushinteger(vm, (SQBool)(_ai_sl_byte != 0));
    00613       return true;
    00614     }
    00615
    00616     case SQSL_NULL: {
    00617       if (vm != NULL) sq_pushnull(vm);
    00618       return true;
    00619     }
    00620
    00621     case SQSL_ARRAY_TABLE_END: {
    00622       return false;
    00623     }
    00624
    00625     default: NOT_REACHED();
    00626   }
    00627 }
    00628
    00629 /* static */ void AIInstance::LoadEmpty()
    00630 {
    00631   SlObject(NULL, _ai_byte);
    00632   /* Check if there was anything saved at all. */
    00633   if (_ai_sl_byte == 0) return;
    00634
    00635   LoadObjects(NULL);
    00636 }
    00637
    00638 void AIInstance::Load(int version)
    00639 {
    00640   if (this->engine == NULL || version == -1) {
    00641     LoadEmpty();
    00642     return;
    00643   }
    00644   HSQUIRRELVM vm = this->engine->GetVM();
    00645
    00646   SlObject(NULL, _ai_byte);
    00647   /* Check if there was anything saved at all. */
    00648   if (_ai_sl_byte == 0) return;
    00649
    00650   /* First remove the value "false" since we have data to load. */
    00651   sq_poptop(vm);
    00652   sq_pushinteger(vm, version);
    00653   LoadObjects(vm);
    00654   sq_pushbool(vm, true);
    00655 }
    00656
    00657 bool AIInstance::CallLoad()
    00658 {
    00659   HSQUIRRELVM vm = this->engine->GetVM();
    00660   /* Is there save data that we should load? */
    00661   SQBool res;
    00662   sq_getbool(vm, -1, &res);
    00663   sq_poptop(vm);
    00664   if (!res) return true;
    00665
    00666   if (!this->engine->MethodExists(*this->instance, "Load")) {
    00667     AILog::Warning("Loading failed: there was data for the AI to load, but the AI does not have a Load() function.");
    00668
    00669     /* Pop the savegame data and version. */
    00670     sq_pop(vm, 2);
    00671     return true;
    00672   }
    00673
    00674   /* Go to the instance-root */
    00675   sq_pushobject(vm, *this->instance);
    00676   /* Find the function-name inside the script */
    00677   sq_pushstring(vm, OTTD2FS("Load"), -1);
    00678   /* Change the "Load" string in a function pointer */
    00679   sq_get(vm, -2);
    00680   /* Push the main instance as "this" object */
    00681   sq_pushobject(vm, *this->instance);
    00682   /* Push the version data and savegame data as arguments */
    00683   sq_push(vm, -5);
    00684   sq_push(vm, -5);
    00685
    00686   /* Call the AI load function. sq_call removes the arguments (but not the
    00687    * function pointer) from the stack. */
    00688   if (SQ_FAILED(sq_call(vm, 3, SQFalse, SQFalse))) return false;
    00689
    00690   /* Pop 1) The version, 2) the savegame data, 3) the object instance, 4) the function pointer. */
    00691   sq_pop(vm, 4);
    00692   return true;
    00693 }